Reduced rotational mass motor assembly for catheter pump

ABSTRACT

A catheter pump is disclosed. The catheter pump can include an impeller and a catheter body having a lumen in which waste fluid flows proximally therethrough during operation of the catheter pump. The catheter pump can also include a drive shaft disposed inside the catheter body. A motor assembly can include a chamber. The motor assembly can include a rotor disposed in the at least a portion of the chamber, the rotor mechanically coupled with a proximal portion of the drive shaft such that rotation of the rotor causes the drive shaft to rotate, the rotor including a longitudinal rotor lumen therethrough. The motor assembly can also comprise a stator assembly disposed about the rotor. During operation of the catheter pump, the waste fluid flows from the lumen into the chamber such that at least a portion of the waste fluid flows proximally through the longitudinal rotor lumen.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.16/946,306, filed Jun. 16, 2020, which is a continuation of U.S. patentapplication Ser. No. 15/635,531 filed on Jun. 28, 2017, now U.S. Pat.No. 10,709,830, issued on Jul. 14, 2020, which is a continuation of andclaims priority to U.S. patent application Ser. No. 15/003,576, filed onJan. 21, 2016, now U.S. Pat. No. 9,770,543, issued on Sep. 26, 2017,which claims priority to U.S. Provisional Patent Application No.62/106,670, filed on Jan. 22, 2015, the contents of which areincorporated by reference herein in their entirety and for all purposes.

BACKGROUND OF THE INVENTION Field of the Invention

This application is directed to catheter pumps for mechanicalcirculatory support of a heart.

Description of the Related Art

Heart disease is a major health problem that has high mortality rate.Physicians increasingly use mechanical circulatory support systems fortreating heart failure. The treatment of acute heart failure requires adevice that can provide support to the patient quickly. Physiciansdesire treatment options that can be deployed quickly andminimally-invasively.

Mechanical circulatory support (MCS) systems and ventricular assistdevices (VADs) have gained greater acceptance for the treatment of acuteheart failure, such as to stabilize a patient after cardiogenic shock,during treatment of acute myocardial infarction (MI) or decompensatedheart failure, or to support a patient during high risk percutaneouscoronary intervention (PCI). An example of an MCS system is a rotaryblood pump placed percutaneously, e.g., via a catheter without asurgical cutdown.

In a conventional approach, a blood pump is inserted into the body andconnected to the cardiovascular system, for example, to the leftventricle and the ascending aorta to assist the pumping function of theheart. Other known applications include pumping venous blood from theright ventricle to the pulmonary artery for support of the right side ofthe heart. Typically, acute circulatory support devices are used toreduce the load on the heart muscle for a period of time, to stabilizethe patient prior to heart transplant or for continuing support.

There is a need for improved mechanical circulatory support devices fortreating acute heart failure. There is a need for devices designed toprovide near full heart flow rate and inserted percutaneously (e.g.,through the femoral artery without a cutdown).

There is a need for a pump with improved performance and clinicaloutcomes. There is a need for a pump that can provide elevated flowrates with reduced risk of hemolysis and thrombosis. There is a need fora pump that can be inserted minimally-invasively and provide sufficientflow rates for various indications while reducing the risk of majoradverse events.

In one aspect, there is a need for a heart pump that can be placedminimally-invasively, for example, through a 15 FR or 12 FR incision. Inone aspect, there is a need for a heart pump that can provide an averageflow rate of 4 Lpm or more during operation, for example, at 62 mmHg ofhead pressure.

While the flow rate of a rotary pump can be increased by rotating theimpeller faster, higher rotational speeds are known to increase the riskof hemolysis, which can lead to adverse outcomes and in some casesdeath. Higher speeds also lead to performance and patient comfortchallenges. Many percutaneous ventricular assist devices (VADs) havedriveshafts between the motor and impeller rotating at high speeds. Somepercutaneous VADs are designed to rotate at speeds of more than 15,000RPM, and in some case more than 25,000 RPM in operation. The vibration,noise, and heat from the motor and driveshaft can cause discomfort tothe patient when positioned, especially when positioned inside the body.Accordingly, there is a need for a device that improves performance andpatient comfort with a high speed motor.

There is a need for a motor configured to drive an operative device,e.g., a impeller, at a distal portion of the pump. It can be importantfor the motor to be configured to allow for percutaneous insertion ofthe pump's impeller.

These and other problems are overcome by the inventions describedherein.

SUMMARY OF THE INVENTION

There is an urgent need for a pumping device that can be insertedpercutaneously and also provide full cardiac rate flows of the left,right, or both the left and right sides of the heart when called for.

In one embodiment, a catheter pump system is disclosed. The catheterpump system can include an impeller and a catheter body having a lumenin which fluid flows proximally therethrough during operation of thecatheter pump. The catheter pump system can include a drive shaftdisposed inside the catheter body and coupled with the impeller at adistal portion of the drive shaft, the drive shaft configured such thatrotation of the drive shaft causes the impeller to rotate. The catheterpump system can include a motor assembly. The motor assembly can includea chamber, at least a portion of the chamber in fluid communication withthe lumen of the catheter body. The motor assembly can also include arotor disposed in the at least a portion of the chamber, the rotormechanically coupled with a proximal portion of the drive shaft suchthat rotation of the rotor causes the drive shaft to rotate. The motorassembly can include a stator assembly disposed about the rotor andconfigured to cause the rotor to rotate. No cooling fins extend outsidean exterior surface of the motor assembly.

In another embodiment, a catheter pump system is disclosed. The catheterpump system can include an impeller and a catheter body having a lumentherethrough, the impeller mechanically coupled with a distal portion ofthe catheter body. The catheter pump system can include a guidewireguide tube disposed through the lumen from a proximal portion of thecatheter pump to a distal portion of the catheter pump, the guidewireguide tube configured to receive a guidewire therein. The catheter pumpsystem can include an end cap secured to a proximal end portion of theguide tube, the end cap configured such that axial movement of the endcap relative to the catheter body causes the guidewire guide tube to beremoved from the catheter pump. The catheter pump system can include aresealable closure device disposed at a proximal portion of the catheterpump, the closure device configured such that when the guidewire guidetube is removed from the catheter pump, the closure device encloses theproximal portion of the catheter pump system.

In another embodiment, a catheter pump system is disclosed. The catheterpump system can include a pump including an impeller for pumping blood.The catheter pump system can include a motor assembly for impartingrotation on the impeller through a drive shaft. The motor assembly cancomprise a stator carrying electrical windings and a rotor disposed inat least a portion of the stator, the rotor mechanically coupled with aproximal portion of the drive shaft. The catheter pump system caninclude a fluid supply system for delivering fluid to the pump duringoperation of the pump and returning at least some of the supplied fluidto a waste reservoir. The fluid supply system can comprise a fluidchannel extending within the stator and a fluid pathway which passesoutside the stator. During operation of the pump, at least a firstportion of the returning fluid can pass through the fluid channel and atleast a second portion of the returning fluid can pass through the fluidpathway.

In another embodiment, a method of operating a pump is disclosed. Thepump can comprise a motor which includes a stator assembly havingwindings and a rotor positioned within the stator assembly. The methodcan include rotating the rotor by selectively energizing the windings.The method can include cooling the motor by flowing a first fluidportion between the stator assembly and the rotor and by flowing asecond fluid portion outside the stator.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the subject matter of this applicationand the various advantages thereof can be realized by reference to thefollowing detailed description, in which reference is made to theaccompanying drawings in which:

FIG. 1A illustrates one embodiment of a catheter pump system with animpeller assembly configured for percutaneous application and operation.

FIG. 1B is a schematic view of one embodiment of a catheter pump systemadapted to be used in the manner illustrated in FIG. 1A.

FIG. 1C is a schematic view of another embodiment of a catheter pumpsystem.

FIG. 2 is a side plan view of a motor assembly of the catheter pumpsystem shown in FIG. 1B, according to various embodiments.

FIG. 3 is a perspective exploded view of the motor assembly shown inFIG. 2 .

FIG. 4A is a side cross-sectional view of the motor assembly shown inFIGS. 2-3 .

FIG. 4B is a side cross-sectional view of a motor assembly, according toanother embodiment.

FIG. 5 is a schematic perspective view of an interface between a distalchamber and a rotor chamber of a flow diverter of the motor assembly,with a stator assembly thereof hidden for ease of illustration.

FIG. 6A is a schematic perspective view of an interface between anoutput shaft of the motor assembly and a drive shaft of the catheterpump system.

FIG. 6B is a cross-sectional perspective view, taken through thelongitudinal axis of the catheter, showing the interface shown in FIG.6A.

FIG. 7 is an image of a cap and a female receiver, with the guide tubenot shown.

More detailed descriptions of various embodiments of components forheart pumps useful to treat patients experiencing cardiac stress,including acute heart failure, are set forth below.

DETAILED DESCRIPTION

This application is generally directed to apparatuses for inducingmotion of a fluid relative to the apparatus. Exemplars of circulatorysupport systems for treating heart failure, and in particular emergentand/or acute heart failure, are disclosed in U.S. Pat. Nos. 4,625,712;4,686,982; 4,747,406; 4,895,557; 4,944,722; 6,176,848; 6,926,662;7,022,100; 7,393,181; 7,841,976; 8,157,719; 8,489,190; 8,597,170;8,721,517 and U.S. Pub. Nos. 2012/0178986 and 2014/0010686, the entirecontents of which patents and publications are incorporated by referencefor all purposes. In addition, this application incorporates byreference in its entirety and for all purposes the subject matterdisclosed in each of the following concurrently filed applications andthe provisional applications to which they claim priority: applicationSer. No. 15/003,682, now issued U.S. Pat. No. 9,675,739, entitled “MOTORASSEMBLY WITH HEAT EXCHANGER FOR CATHETER PUMP,” filed on the same dateas this application and claiming priority to U.S. Provisional PatentApplication No. 62/106,675; and application Ser. No. 15/003,696, nowissued U.S. Pat. No. 9,675,738, entitled “ATTACHMENT MECHANISMS FORMOTOR OF CATHETER PUMP,” filed on the same date as this application andclaiming priority to U.S. Provisional Patent Application No. 62/106,673.

In one example, an impeller can be coupled at a distal portion of theapparatus. Some embodiments generally relate to various configurationsfor a motor assembly adapted to drive an impeller at a distal end of acatheter pump, e.g., a percutaneous heart pump. In such applications,the disclosed motor assembly is disposed outside the patient in someembodiments. In other embodiments, the disclosed motor assembly and/orfeatures of the motor are miniaturized and sized to be inserted withinthe body, e.g., within the vasculature.

FIGS. 1A-1B show aspects of an exemplary catheter pump 100A that canprovide high performance, e.g., high blood flow rates. As shown in FIG.1B, the pump 100A includes a motor assembly 1 driven by a console 122,which can include an electronic controller and various fluid handlingsystems. The console 122 directs the operation of the motor 1 and aninfusion system that supplies a flow of fluid in the pump 100A.Additional details regarding the console 122 may be found throughoutU.S. Patent Publication No. US 2014/0275725, the contents of which areincorporated by reference herein in their entirety and for all purposes.

The pump 100A includes a catheter assembly 101 that can be coupled withthe motor assembly 1 and can house an impeller in an impeller assembly116A within a distal portion of the catheter assembly 101 of the pump100A. In various embodiments, the impeller is rotated remotely by themotor 1 when the pump 100A is operating. For example, the motor 1 can bedisposed outside the patient. In some embodiments, the motor 1 isseparate from the console 122, e.g., to be placed closer to the patient.In the exemplary system the pump is placed in the patient in a sterileenvironment and the console is outside the sterile environment. In oneembodiment, the motor is disposed on the sterile side of the system. Inother embodiments, the motor 1 is part of the console 122.

In still other embodiments, the motor 1 is miniaturized to be insertableinto the patient. For example, FIG. 1C is a schematic view of anotherembodiment of a catheter pump system. FIG. 1C is similar to FIG. 1B,except the motor 1 is miniaturized for insertion into the body. As shownin FIG. 1C, for example, the motor 1 can be disposed proximal theimpeller assembly 116A. The motor 1 can be generally similar to themotor assembly shown in FIG. 2 , except the motor 1 is sized and shapedto be inserted into the patient's vasculature. One or more electricallines may extend from the motor to the console outside the patient. Theelectrical lines can send signals for controlling the operation of themotor. Such embodiments allow a drive shaft coupled with the impellerand disposed within the catheter assembly 101 to be much shorter, e.g.,shorter than the distance from the aortic valve to the aortic arch(about 5 cm or less). Some examples of miniaturized motor catheter pumpsand related components and methods are discussed in U.S. Pat. Nos.5,964,694; 6,007,478; 6,178,922; and 6,176,848, all of which are herebyincorporated by reference herein in their entirety for all purposes.Various embodiments of the motor assembly 1 are disclosed herein,including embodiments having a rotor disposed within a stator assembly.In various embodiments, waste fluid can pass through a housing in whichthe rotor is disposed to help cool the motor assembly 1.

FIG. 1A illustrates one use of the catheter pump 100A. A distal portionof the pump 100A including a catheter assembly including the impellerassembly 116A is placed in the left ventricle LV of the heart to pumpblood from the LV into the aorta. The pump 100A can be used in this wayto treat a wide range of heart failure patient populations including,but not limited to, cardiogenic shock (such as acute myocardialinfarction, acute decompensated heart failure, and postcardiotomy),myocarditis, and others. The pump can also be used for various otherindications including to support a patient during a cardiac inventionsuch as a high-risk percutaneous coronary intervention (PCI) or VFablation. One convenient manner of placement of the distal portion ofthe pump 100A in the heart is by percutaneous access and delivery usinga modified Seldinger technique or other methods familiar tocardiologists. These approaches enable the pump 100A to be used inemergency medicine, a catheter lab and in other medical settings.Modifications can also enable the pump 100A to support the right side ofthe heart. Example modifications that could be used for right sidesupport include providing delivery features and/or shaping a distalportion that is to be placed through at least one heart valve from thevenous side, such as is discussed in U.S. Pat. Nos. 6,544,216;7,070,555; and US 2012-0203056A1, all of which are hereby incorporatedby reference herein in their entirety for all purposes.

The impeller assembly 116A can be expandable and collapsible. In thecollapsed state, the distal end of the catheter pump 100A can beadvanced to the heart, for example, through an artery. In the expandedstate the impeller assembly 116A is able to pump blood at relativelyhigh flow rates. In particular, the expandable cannula and impellerconfiguration allows for decoupling of the insertion size and flow rate,in other words, it allows for higher flow rates than would be possiblethrough a lumen limited to the insertion size with all other thingsbeing equal. In FIGS. 1A and 1B, the impeller assembly 116A isillustrated in the expanded state. The collapsed state can be providedby advancing a distal end 170A of an elongate body 174A distally overthe impeller assembly 116A to cause the impeller assembly 116A tocollapse. This provides an outer profile throughout the catheterassembly and catheter pump 100A that is of small diameter duringinsertion, for example, to a catheter size of about 12.5 FR in variousarrangements. In other embodiments, the impeller assembly 116A is notexpandable.

The mechanical components rotatably supporting the impeller within theimpeller assembly 116A permit relatively high rotational speeds whilecontrolling heat and particle generation that can come with high speeds.The infusion system delivers a cooling and lubricating solution to thedistal portion of the catheter pump 100A for these purposes. The spacefor delivery of this fluid is extremely limited. Some of the space isalso used for return of the fluid as waste fluid. Providing secureconnection and reliable routing of fluid into and out of the catheterpump 100A is critical and challenging in view of the small profile ofthe catheter assembly 101.

When activated, the catheter pump 100A can effectively support, restoreand/or increase the flow of blood out of the heart and through thepatient's vascular system. In various embodiments disclosed herein, thepump 100A can be configured to produce a maximum flow rate (e.g. low mmHg) of greater than 4 Lpm, greater than 4.5 Lpm, greater than 5 Lpm,greater than 5.5 Lpm, greater than 6 Lpm, greater than 6.5 Lpm, greaterthan 7 Lpm, greater than 7.5 Lpm, greater than 8 Lpm, greater than 9Lpm, or greater than 10 Lpm. In various embodiments, the pump 100A canbe configured to produce an average flow rate at 62 mmHg of greater than2 Lpm, greater than 2.5 Lpm, greater than 3 Lpm, greater than 3.5 Lpm,greater than 4 Lpm, greater than 4.25 Lpm, greater than 4.5 Lpm, greaterthan 5 Lpm, greater than 5.5 Lpm, or greater than 6 Lpm.

Various aspects of the pump and associated components can be combinedwith or substituted for those disclosed in U.S. Pat. Nos. 7,393,181;8,376,707; 7,841,976; 7,022,100; and 7,998,054, and in U.S. Pub. Nos.2011/0004046; 2012/0178986; 2012/0172655; 2012/0178985; and2012/0004495, the entire contents of each of which are incorporatedherein for all purposes by reference. In addition, this applicationincorporates by reference in its entirety and for all purposes thesubject matter disclosed in each of the following applications: U.S.Patent Publication No. US 2013/0303970, entitled “DISTAL BEARINGSUPPORT,” filed on Mar. 13, 2013; U.S. Patent Publication No. US2014/0275725, entitled “FLUID HANDLING SYSTEM,” filed on Mar. 11, 2014;U.S. Patent Publication No. US 2013/0303969, entitled “SHEATH SYSTEM FORCATHETER PUMP,” filed on Mar. 13, 2013; U.S. Patent Publication No. US2013/0303830, entitled “IMPELLER FOR CATHETER PUMP,” filed on Mar. 13,2013; U.S. Patent Publication No. US 2014/0012065, entitled “CATHETERPUMP,” filed on Mar. 13, 2013; and U.S. Patent Publication No. US2014/0010686, entitled “MOTOR ASSEMBLY FOR CATHETER PUMP,” filed on Mar.13, 2013.

Moving from a distal end 1450 of the catheter assembly 101 of thecatheter pump 100A of FIG. 1B to a proximal end 1455, a primingapparatus 1400 can be disposed over the impeller assembly 116A. Asexplained above, the impeller assembly 116A can include an expandablecannula or housing and an impeller with one or more blades. As theimpeller rotates, blood can be pumped proximally (or distally in someimplementations) to function as a cardiac assist device.

In FIG. 1B the priming apparatus 1400 can be disposed over the impellerassembly 116A near the distal end portion 170A of the elongate body174A. The priming apparatus 1400 can be used in connection with aprocedure to expel air from the impeller assembly 116A, e.g., any airthat is trapped within the housing or that remains within the elongatebody 174A near the distal end 170A. For example, the priming proceduremay be performed before the pump is inserted into the patient's vascularsystem, so that air bubbles are not allowed to enter and/or injure thepatient. The priming apparatus 1400 can include a primer housing 1401configured to be disposed around both the elongate body 174A and theimpeller assembly 116A. A sealing cap 1406 can be applied to theproximal end 1402 of the primer housing 1401 to substantially seal thepriming apparatus 1400 for priming, i.e., so that air does notproximally enter the elongate body 174A and also so that priming fluiddoes not flow out of the proximal end of the housing 1401. The sealingcap 1406 can couple to the primer housing 1401 in any way known to askilled artisan. In some embodiments, the sealing cap 1406 is threadedonto the primer housing by way of a threaded connector 1405 located atthe proximal end 1402 of the primer housing 1401. The sealing cap 1406can include a sealing recess disposed at the distal end of the sealingcap 1406. The sealing recess can be configured to allow the elongatebody 174A to pass through the sealing cap 1406.

The priming operation can proceed by introducing fluid into the sealedpriming apparatus 1400 to expel air from the impeller assembly 116A andthe elongate body 174A. Fluid can be introduced into the primingapparatus 1400 in a variety of ways. For example, fluid can beintroduced distally through the elongate body 174A into the primingapparatus 1400. In other embodiments, an inlet, such as a luer, canoptionally be formed on a side of the primer housing 1401 to allow forintroduction of fluid into the priming apparatus 1400. A gas permeablemembrane can be disposed on a distal end 1404 of the primer housing1401. The gas permeable membrane can permit air to escape from theprimer housing 1401 during priming.

The priming apparatus 1400 also can advantageously be configured tocollapse an expandable portion of the catheter pump 100A. The primerhousing 1401 can include a funnel 1415 where the inner diameter of thehousing decreases from distal to proximal. The funnel may be gentlycurved such that relative proximal movement of the impeller housingcauses the impeller housing to be collapsed by the funnel 1415. Duringor after the impeller housing has been fully collapsed, the distal end170A of the elongate body 174A can be moved distally relative to thecollapsed housing. After the impeller housing is fully collapsed andretracted into the elongate body 174A of the sheath assembly, thecatheter pump 100A can be removed from the priming housing 1400 before apercutaneous heart procedure is performed, e.g., before the pump 100A isactivated to pump blood. The embodiments disclosed herein may beimplemented such that the total time for infusing the system isminimized or reduced. For example, in some implementations, the time tofully infuse the system can be about six minutes or less. In otherimplementations, the time to infuse can be about three minutes or less.In yet other implementations, the total time to infuse the system can beabout 45 seconds or less. It should be appreciated that lower times toinfuse can be advantageous for use with cardiovascular patients.

With continued reference to FIG. 1B, the elongate body 174A extends fromthe impeller assembly 116A in a proximal direction to an fluid supplydevice 195. The fluid supply device is configured to allow for fluid toenter the catheter assembly 101 of the catheter pump 100A and/or forwaste fluid to leave the catheter assembly 101 of the catheter pump100A. A catheter body 120A (which also passes through the elongate body174A) can extend proximally and couple to the motor assembly 1. Asdiscussed in more detail herein, the motor assembly 1 can provide torqueto a drive shaft that extends from the motor assembly 1 through thecatheter body 120A to couple to an impeller shaft at or proximal to theimpeller assembly 116A. The catheter body 120A can pass within theelongate body 174A such that the external elongate body 174A can axiallytranslate relative to the internal catheter body 120A.

Further, as shown in FIG. 1B, a fluid supply line 6 can fluidly couplewith the console 122 to supply saline or other fluid to the catheterpump 100A. The saline or other fluid can pass through an internal lumenof the internal catheter body 120A and can provide lubrication to theimpeller assembly 116A and/or chemicals to the patient. The suppliedfluid (e.g., saline or glucose solution) can be supplied to the patientby way of the catheter body 120A at any suitable flow rate. For example,in various embodiments, the fluid is supplied to the patient at a flowrate in a range of 15 mL/hr to 50 mL/hr, or more particularly, in arange of 20 mL/hr to 40 mL/hr, or more particularly, in a range of 25mL/hr to 35 mL/hr. One or more electrical conduits 124 can provideelectrical communication between the console 122 and the motor assembly1. A controller within the console 122 can control the operation of themotor assembly 1 during use.

In addition, a waste line 7 can extend from the motor assembly 1 to awaste reservoir 126. Waste fluid from the catheter pump 100A can passthrough the motor assembly 1 and out to the reservoir 126 by way of thewaste line 7. In various embodiments, the waste fluid flows to the motorassembly 1 and the reservoir 126 at a flow rate which is lower than thatat which the fluid is supplied to the patient. For example, some of thesupplied fluid may flow out of the catheter body 120A and into thepatient by way of one or more bearings. The waste fluid (e.g., a portionof the fluid which passes proximally back through the motor from thepatient) may flow through the motor assembly 1 at any suitable flowrate, e.g., at a flow rate in a range of 5 mL/hr to 20 mL/hr, or moreparticularly, in a range of 10 mL/hr to 15 mL/hr.

Access can be provided to a proximal end of the catheter assembly 101 ofthe catheter pump 100A prior to or during use. In one configuration, thecatheter assembly 101 is delivered over a guidewire 235. The guidewire235 may be conveniently extended through the entire length of thecatheter assembly 101 of the catheter pump 100A and out of a proximalend 1455 of the catheter assembly 101. In various embodiments, theconnection between the motor assembly 1 and the catheter assembly 101 isconfigured to be permanent, such that the catheter pump, the motorhousing and the motor are disposable components. However, in otherimplementations, the coupling between the motor housing and the catheterassembly 101 is disengageable, such that the motor and motor housing canbe decoupled from the catheter assembly 101 after use. In suchembodiments, the catheter assembly 101 distal of the motor can bedisposable, and the motor and motor housing can be re-usable.

In addition, FIG. 1B illustrates the guidewire 235 extending from aproximal guidewire opening 237 in the motor assembly 1. Before insertingthe catheter assembly 101 of the catheter pump 100A into a patient, aclinician may insert the guidewire 235 through the patient's vascularsystem to the heart to prepare a path for the impeller assembly 116A tothe heart. In some embodiments, the catheter pump 100A can include aguidewire guide tube 20 (see FIG. 3 ) passing through a central internallumen of the catheter pump 100A from the proximal guidewire opening 237.The guidewire guide tube 20 can be pre-installed in the catheter pump100A to provide the clinician with a preformed pathway along which toinsert the guidewire 235.

In one approach, the guidewire 235 is first placed through a needle intoa peripheral blood vessel, and along the path between that blood vesseland the heart and into a heart chamber, e.g., into the left ventricle.Thereafter, a distal end opening of the catheter pump 100A and guidewireguide tube 20 can be advanced over the proximal end of the guidewire 235to enable delivery to the catheter pump 100A. After the proximal end ofthe guidewire 235 is urged proximally within the catheter pump 100A andemerges from the guidewire opening 237 and/or guidewire guide tube 20,the catheter pump 100A can be advanced into the patient. In one method,the guidewire guide tube 20 is withdrawn proximally while holding thecatheter pump 100A.

Alternatively, the clinician can thus insert the guidewire 235 throughthe proximal guidewire opening 237 and urge the guidewire 235 along theguidewire guide tube. The clinician can continue urging the guidewire235 through the patient's vascular system until the distal end of theguidewire 235 is positioned in the desired position, e.g., in a chamberof the patient's heart, a major blood vessel or other source of blood.As shown in FIG. 1B, a proximal end portion of the guidewire 235 canextend from the proximal guidewire opening 237. Once the distal end ofthe guidewire 235 is positioned in the heart, the clinician can maneuverthe impeller assembly 116A over the guidewire 235 until the impellerassembly 116A reaches the distal end of the guidewire 235 in the heart,blood vessel or other source of blood. The clinician can remove theguidewire 235 and the guidewire guide tube. The guidewire guide tube canalso be removed before or after the guidewire 235 is removed in someimplementations.

After removing at least the guidewire 235, the clinician can activatethe motor 1 to rotate the impeller and begin operation of the pump 100A.

FIGS. 2 and 3 further illustrate aspects of embodiments of the motorassembly 1 shown in FIG. 1B. The motor assembly 1 can include a statorassembly 2 (FIGS. 2-3 ) and a rotor 15 disposed radially within thestator assembly 2 (FIG. 3 ). The motor assembly 1 also includes a flowdiverter 3, which can be configured as a manifold for directing fluidthrough one or more passages in the catheter pump 100A. In some cases,the flow diverter 3 is at least partially disposed radially between thestator assembly 2 and the rotor 15 (FIGS. 2-3 ). The flow diverter 3 canbe fluidly sealed about the rotor 15 and a proximal portion 56 of thecatheter body 120A. The seal prevents leakage and also can prevent thefluid from contacting the stator assembly 2. The flow diverter 3 caninclude a distal chamber 5 within which the proximal portion 56 of thecatheter body 120A is disposed and a rotor chamber 4 within which therotor 15 is disposed. The flow diverter 3 can also have a proximalchamber 10 in some embodiments. Where provided, the distal chamber 5,rotor chamber 4, and proximal chamber 10 can be in fluid communicationwithin the flow diverter 3. One or more flanges 11A, 11B canmechanically couple the flow diverter 3 to an external housing (notshown). The flanges 11A, 11B are examples of mount structures that canbe provided, which can include in various embodiments dampers to isolatethe motor assembly 1 from external shock or vibration. In someembodiments, mount structures can include dampers configured to isolatean outer housing or the environment external to the motor assembly 1from shock or vibration generated by the motor assembly 1. Further, apressure sensor assembly 12 is configured to measure the pressure at adistal portion of the catheter pump 100A by, for example, measuring thepressure of a column of fluid that extends distally through a lumen ofthe catheter body 120A. In addition, the guidewire guide tube 20 canextend proximally through the motor assembly 1 and can terminate at atube end cap 8. As explained above, the guidewire 235 can be insertedwithin the guide tube 20 for guiding the catheter pump 100A to theheart.

The rotor 15 and stator assembly 2 can be configured as or be componentsof a frameless-style motor for driving the impeller assembly 116A at thedistal end of the pump 100A. For example, the stator assembly 2 cancomprise a stator and a plurality of conductive windings producing acontrolled magnetic field. The windings can be wrapped about or in astationary portion 65 of the stator assembly 2. The rotor 15 cancomprise a magnetic material, e.g., can include one or more permanentmagnets. In some embodiments, the rotor 15 can comprise a multi-polemagnet, e.g., a four-pole or six-pole magnet. Providing changingelectrical currents through the windings of the stator assembly 2 cancreate magnetic fields that interact with the rotor 15 to cause therotor 15 to rotate. This is commonly referred to as commutation. Theconsole 122 can provide electrical power (e.g., 24V) to the statorassembly 2 to drive the motor assembly 1. One or more leads 9 canelectrically communicate with the stator assembly 2, e.g., with one ormore Hall sensors used to detect the speed and/or position of the motor.In other embodiments, other sensors (e.g., optical sensors) can be usedto measure motor speed. The rotor 15 can be secured to an output shaft13 (which can comprise a hollow shaft with a central lumen) such thatrotation of the rotor 15 causes the output shaft 13 to rotate. Invarious embodiments, the motor assembly 1 can comprise a direct current(DC) brushless motor. In other embodiments, other types of motors can beused, such as AC motors, etc. As shown in FIG. 3 , first and secondjournal bearings 18A, 18B can be provided about the output shaft 13 toradially and/or longitudinally center the output shaft 13 and therebythe rotor 15 relative to the stator assembly 2.

FIG. 4A shows that the output shaft 13 (which is secured to the rotor15) can be mechanically coupled with the proximal end portion of a driveshaft 16. The drive shaft 16 extends distally through an internal lumenof the catheter body 120A. A distal end portion of the drive shaft 16 ismechanically connected with the impeller. Thus, rotation of the rotor 15causes the output shaft 13 to rotate, which, in turn, causes the driveshaft 16 and the impeller to rotate. FIG. 4A also shows that a lumen 55can extend through the output shaft 13 and the rotor 15. In certainembodiments, the lumen 55 is coupled with a lumen of the catheter body120A such that the guidewire guide tube 20 can extend through the lumen55 within the rotor 15 and into the lumen of the catheter body 120A. Inaddition, the drive shaft 16 comprises a braided shaft having aninternal lumen. The braided drive shaft 16 or cable can be permeable toliquid such that supply fluid or waste fluid can flow from outside thedrive shaft 16 to within the internal lumen of the drive shaft 16 (andvice versa).

FIG. 4A shows the tube end cap 8 welded or otherwise secured to aproximal end portion of the guide tube 20. The cap 8 can be removablyengaged (e.g., screwed or otherwise removably locked) over a femalereceiver 71 that is secured in a proximal end of the proximal chamber10. For example, the proximal end of the female receiver 71 can bedisposed in a counterbore of the cap 8, while the guide tube 20 extendsthrough the central opening of the cap 8. In a locked configuration, oneor more tabs of the receiver 71 can be rotated such that the tab(s)slide under a corresponding tab in the counterbore of the cap 8. In anunlocked configuration, the tab(s) of the receiver 71 can be rotatedrelative to the tabs of the cap 8. FIG. 7 shows one embodiment of thecap 8 and of the female receiver 71 that can be coupled with the guidetube 20 (not shown). In the illustrated embodiment, the cap 8 can befixed to the guide tube 20; in other embodiments, the receiver 71 can befixed to the guide tube 20. Engaging the cap 8 to the receiver 71 canadvantageously prevent the guide tube 20 from accidentally being removedfrom or slid within the catheter pump 100A, e.g., if the patient orclinician impacts the cap 8. To remove the guide tube 20 (e.g., afterdelivery of the impeller assembly 116A to the heart), the clinician candisengage the cap 8 from the receiver 71 and can pull the guide tube 20from the catheter pump 100A, for example, by pulling proximally on theend cap 8. A resealable septum 72 (e.g., a resealable closure member)can be provided at the proximal end of the flow diverter 3, e.g., nearthe distal end of the cap 8 when the cap 8 is in place. When theguidewire guide tube 20 is removed from the pump 100A, the septum 72will naturally reseal the pathway proximally from the motor assembly 1such that fluid does not exit the assembly 1. An advantage of theassembly described herein is that the cap 8 is locked and will not bedislodged without rotating and unlocking cap 8 from receiver 71. With aconventional torquer assembly, the cap 8 can slide axially if it isinadvertently bumped by the patient or clinician. This potentiallyresults in the guide tube 20 being pulled out from the distal-most endof the impeller assembly 116A, and because the guide tube cannot bere-inserted, the clinician either has to use the catheter pump 100Awithout a guide or get a new pump.

With continued reference to FIG. 4A, it can be important to ensure thatthe motor assembly 1 is adequately cooled. In various embodiments, itcan be important to provide a heat removal system to limit buildup ofheat in the motor assembly 1 during operation. For example, it can beimportant to maintain external surfaces of the motor assembly 1 at atemperature less than about 40° C. if the motor assembly 1 is positionednear the patient. For example, an external surface of an externalhousing of the motor assembly 1 may be kept at or below thistemperature. In some respects, regulatory guidelines can require that nopart in contact with skin exceed 40° C. To that end, various strategiesfor heat management are employed by the inventions described herein. Itshould be appreciated that, as used herein, cooling refers totransferring away or dissipating heat, and in certain respects, coolingis used interchangeably with removing heat.

Various components of the motor assembly 1 generate heat. For example,moving parts within the motor assembly 1 (e.g., the rotating outputshaft 13 and/or drive shaft 16) can generate heat by virtue of lossesthrough friction, vibrations, and the like, which may increase theoverall temperature of the motor assembly 1. Further, heat can begenerated by the electrical current flowing through the stator assembly2 and/or by induction heating caused by conductive components inside arotating magnetic field. Furthermore, friction between the bearings 18and the output shaft 13 and/or friction between the drive shaft 16 andthe inner wall of catheter body 120A may also generate undesirable heatin the motor assembly. Inadequate cooling can result in temperatureincreases of the motor assembly 1, which can present patient discomfort,health risks, or performance losses. This can lead to undesirable usagelimitations and engineering complexity, for example, by requiringmitigation for differential heat expansion of adjacent components ofdifferent materials. Accordingly, various embodiments disclosed hereincan advantageously transfer away generated heat and cool the motorassembly 1 such that the operating temperature of the assembly 1 issufficiently low to avoid such complexities of use or operation and/orother components of the system. For example, various heat transfercomponents can be used to move heat away from thermal generation sourcesand away from the patient. Various aspects of the illustrated deviceherein are designed to reduce the risk of hot spots, reduce the risk ofheat spikes, and/or improve heat dissipation to the environment and awayfrom the patient.

In some embodiments, the catheter pump makes use of the fluid supplysystem already embedded in the pump to cool the motor assembly 1 andhousing. In some embodiments, heat absorbing capacity of fluid flowingthrough the flow diverter 3 is used to cool the motor assembly 1. Asshown in FIG. 4A, the supply line 6 can supply fluid 35 from a source(e.g., a fluid bag) to an outer lumen 57 of the catheter body 120A. Thesupplied fluid 35 can travel distally toward the impeller assembly 116Ato lubricate rotating components in the catheter assembly 101 and/orsupply fluid to the patient. A seal 19 (e.g., an o-ring) can be providedbetween the rotor housing 4 and the distal housing 5 to prevent backflowof the fluid 35 into the rotor housing 4. In this context, backflow isflow of fluid 35 proximally into the distal housing 5 rather thandistally within the lumen 57. Such flow is to be prevented to ensurethat the fluid 35 is initially exposed to moving parts in a distalportion of the catheter assembly 101 to lubricate and cool such distalcomponents.

Fluid from the catheter pump 100A can flow proximally through an innerlumen 58 of the catheter body 120A. For example, after initially coolingdistal components some or all of the supplied fluid 35 can flow withinthe drive shaft 16 and/or around the periphery of the drive shaft 16.After initially cooling distal components some or all of the suppliedfluid 35 can flow in a space disposed radially between the drive shaft16 and the catheter body 120A. The proximally-flowing fluid can flowalong a flow pathway which removes heat from the motor assembly 1. Asshown in FIG. 4A, the proximally-flowing fluid (or other cooling fluid)can flow into the rotor chamber 4 of the flow diverter 3. A firstportion 17A of the waste fluid can pass proximally through the motorassembly 1 about a periphery of the rotor 15, e.g., in a gap between therotor 15 and a wall of the flow diverter 3. In some embodiments, asecond portion 17B of the waste fluid can pass proximally through themotor assembly 1 through the lumen 55 of the output shaft 13. The fluidportions 17A, 17B can pass from the rotor chamber 4 into the proximalchamber 10 of the flow diverter 3, where the fluid 17A, 17B can flow outto a reservoir (not shown) by way of line 7.

The embodiment of FIG. 4A can advantageously convey heat from the heatgenerating components (e.g., rotor 15 and stator assembly 2) into thefluid 35 or other cooling fluid and to the reservoir 126 by way of thewaste line 7. For example, the first portion 17A of the fluid thatpasses about the periphery of the rotor 15 can direct heat radiallyoutward from the rotor 15 and other components of the flow diverter 3.The first portion 17A of the fluid that passes about the periphery ofthe rotor 15 can direct heat inward from the stator assembly 2 and othercomponents outside the flow diverter 3. The second portion 17B of thewaste fluid can draw heat radially inward, e.g., radially inward fromthe rotor 15 and other components of the flow diverter 3. As the heatfrom the motor assembly 1 is conveyed away by way of the fluid to thereservoir 126, the temperature of the motor housing can be reduced ormaintained at a suitable operational temperature for the medical staff,the patient and/or for the catheter pump system. A gap between thestator assembly and the external motor housing (e.g., the outer shell orhousing surrounding the motor assembly) comprises air, which is a good,natural insulator. Thus, the heat from the stator assembly 2 isnaturally transferred to the waste line rather than dissipating out thesides of the housing of the motor assembly 1.

FIG. 4B is a side cross-sectional view of a motor assembly 1, accordingto another embodiment. Unless otherwise noted, components numberedsimilar to those in FIG. 4A represent the same or similar components andfunctionalities. For example, as with the embodiment of FIG. 4A, in theembodiment of FIG. 4A, a first portion 17A of the fluid can passproximally through the motor assembly 1 about a periphery of the rotor15, e.g., in a gap between the rotor 15 and a wall of the flow diverter3. In some embodiments, a second portion 17B of the fluid can passproximally through the motor assembly 1 through the lumen 55 of theoutput shaft 13. The fluid portions 17A, 17B can pass from the rotorchamber 4 into the proximal chamber 10 of the flow diverter 3, where thefluid 17A, 17B can flow out to a reservoir (not shown) by way of line 7.Thus, the fluid portions 17A, 17B can flow along a first fluid pathwayor channel within the flow diverter 3 which is disposed inside thestator 2.

Unlike the embodiment of FIG. 4A, however, in the embodiment of FIG. 4B,a third portion 17C of the fluid can be shunted around the rotor 15 andstator assembly 2 along a second fluid pathway or channel. For example,as shown in FIG. 4B, the third portion 17C of the proximally-flowingfluid can be withdrawn from the inner lumen 58 of the catheter body 120Aby way of a suitable conduit and fluid connector. The third fluidportion 17C can bypass the motor assembly 1 and can be conveyed to thewaste reservoir by a suitable waste line, which may be the same as ordifferent from the waste line 7. The third portion 17C of theproximally-flowing fluid can be more than, less than, or about the samein volume as the combined volume of the first and second fluid portions17A, 17B. In other embodiments, rather than being conveyed directly to awaste line, the third portion 17C can be transported by a conduit to aheat exchanger to further cool the motor assembly 1. For example, thethird fluid portion 17C can be conveyed to coiled tubing or a tubularsleeve disposed about the stator assembly 2, as shown in variousembodiments of the following concurrently filed application: applicationSer. No. 15/003,682, now issued U.S. Pat. No. 9,675,739, entitled “MOTORASSEMBLY WITH HEAT EXCHANGER FOR CATHETER PUMP,” filed on the same dateas this application and which is expressly incorporated by referenceherein in its entirety and for all purposes.

The embodiment of FIG. 4B may be desirable in arrangements in which thefirst and second fluid portions 17A, 17B become too hot and/or otherwiseineffective at cooling the motor assembly 1. For example, in somearrangements, the motor assembly 1 may heat the first and second fluidportions 17A, 17B passing inside the flow diverter 3 to such a degreethat the temperatures of the fluid portions 17A, 17B and/or the motorassembly 1 rise to unacceptable levels. In such a situation, it may bedesirable to shunt some, most, or all of the proximally-flowing fluidaround the motor assembly 1 along the second fluid pathway. For example,in some embodiments, the first and second fluid portions 17A, 17B maypass through the flow diverter 3 along the first fluid pathway at a flowrate less than that provided in the embodiment of FIG. 4A. In theembodiment of FIG. 4A, the fluid may flow back proximally through theflow diverter at rate such that the combined flow rate of the first andsecond portions 17A, 17B is in a range of 5 mL/hr to 20 mL/hr, or moreparticularly, in a range of 10 mL/hr to 15 mL/hr.

In the embodiment of FIG. 4B, however, some, most, or all of theproximally-flowing fluid is diverted around the flow diverter 3 andother components of the motor along the second fluid pathway as thethird fluid portion 17C. The amount of the fluid portion 17C divertedaround the motor assembly 1 can be any suitable amount so as to maintainan adequate external temperature of the motor housing 1. For example, inone embodiment, the third fluid portion 17C represents a relativelysmall volume of fluid diverted from the inner lumen 58. In oneembodiment, the third fluid portion 17C flows around the motor assembly1 at a flow rate in a range of 1 mL/hr to 30 mL/hr. In one embodiment,the third fluid portion 17C flows around the motor assembly 1 at a flowrate in a range of 1 mL/hr to 5 mL/hr, or in a range of 1 mL/hr to 3mL/hr. In one embodiment, the third fluid portion 17C flows around themotor assembly 1 at a flow rate in a range of 10 mL/hr to 50 mL/hr. Inanother embodiment, the third fluid portion 17C represents a majority ofthe fluid diverted from the inner lumen 58. For example, in such anembodiment, the third fluid portion 17C may have a flow rate in a rangeof 5.5 mL/hr to 12 mL/hr, in a range of 5.5 mL/hr to 10 mL/hr, in arange of 5.5 mL/hr to 8 mL/hr, in a range of 5.5 mL/hr to 7 mL/hr, in arange of 10 mL/hr to 14 mL/hr, or in a range of 8 mL/hr to 12 mL/hr.Advantageously, diverting some of the proximally-flowing fluid aroundthe motor assembly 1 can improve the transfer of heat away from themotor assembly 1, for example, in situations in which the first andsecond fluid portions 17A, 17B become too hot.

Moreover, in some embodiments, the console 122 can be configured tochange the amount of the third fluid portion 17C flowing along thesecond fluid pathway before and/or during a treatment procedure toadjust the volume of fluid that is diverted from the inner lumen 58around the motor assembly 1. For example, the console 122 can sendinstructions to a pump (such as a peristaltic pump) to adjust the flowrate of fluid shunted around the motor assembly 1. In some embodiments,a common pump is applied to all three fluid portions 17A-17C. In otherembodiments, one pump is applied to draw the first and second fluidportions 17A, 17B, and a separate pump is applied to draw the thirdfluid portion 17C.

In still other embodiments, all or substantially all the fluid flowingproximally through the inner lumen 58 is shunted around the motorassembly 1 along the second fluid pathway. The shunted third fluidportion 17C can be diverted to a waste reservoir and/or to a heatexchanger disposed about the stator assembly 2, as explained above. Insuch embodiments, all (100%) or substantially all (i.e., between 90% and100%) of the proximally-flowing fluid does not flow within the motorassembly 1 (e.g., within the flow diverter 3), but is instead divertedaround the motor assembly 1. Thus, in some embodiments, there may be noproximally-flowing fluid portions 17A, 17B within the flow diverter 3.In such arrangements, the motor assembly 1 may be adequately cooledwithout the fluid portions 17A, 17B flowing proximally through the flowdiverter 3. The fluid flowing proximally through the inner lumen 58 mayalso provide sufficient pressure so as to prevent air or other gasesfrom passing distally through the catheter body 120A to the patient.

Advantageously, the embodiments disclosed in FIGS. 1A-4B can adequatelyremove heat from the motor assembly 1 without requiring the use ofexternal cooling fins exposed to the outside environs. That is, thethermal performance of the heat removal systems disclosed in FIGS. 2-4Bcan adequately reduce the temperature of the outer surface of the motorhousing without using cooling fins exposed outside of the motor housing(e.g., outside of an exterior surface of the motor assembly 1) to theambient environment. Rather, the heat removal systems may be disposedentirely within the motor housing, e.g., within the housing whichencloses the rotor and stator. For example, in some embodiments, thesystems disclosed in FIGS. 1A-4B can ensure that the temperature of theexterior surface of the motor assembly 1 is not more than about 40° C.In some embodiments, the systems disclosed in FIGS. 1A-4B can ensurethat the temperature of the exterior surface of the motor assembly 1 isin a range of 15° C. to 42° C., or more particularly in a range of 20°C. to 42° C., in a range of 20° C. to 40° C., in a range of 20° C. to35° C., or in a range of 20° C. to 30° C., without requiring the use ofexternal cooling fins exposed outside the motor housing.

Still other thermal management techniques may be suitable in combinationwith the embodiments disclosed herein. For example, U.S. PatentPublication Nos. 2014/0031606 and 2011/0295345, which are incorporatedby reference herein in their entirety and for all purposes, describestructures and materials which may be incorporated in place of or inaddition to the devices described above to dissipate heat effectively,as will be understood by one of skill from the description herein.

FIG. 5 is a schematic perspective view of an interface between thedistal chamber 5 and the rotor chamber 4 of the flow diverter 3, withthe stator assembly 2 hidden for ease of illustration. FIG. 5 shows theoutput shaft 13 coupled with a proximal portion of the drive shaft 16through an aperture in the flange 11B. The journal bearings 18A (FIGS. 3and 5 ) and 18B (FIG. 3 ) can be provided on opposite axial sides of therotor 15 to help maintain the rotor 15 in radial alignment with therotor chamber 4 and in axial alignment with the stator assembly 2.Improving radial alignment of the rotor 15 and output shaft 13 relativeto the rotor chamber 4 can reduce or eliminate eccentricity duringrotation, which can reduce vibrations. Improving axial alignmentrelative to the stator assembly 2 can advantageously improve theefficiency of the motor assembly 1 by ensuring that the windings of thestator assembly 2 are adequately aligned with the rotor 15. In variousembodiments, the journal bearings 18A, 18B can be rotationally decoupledwith the output shaft 13 such that the output shaft 13 can rotaterelative to the bearings 18A, 18B. In some embodiments, the journalbearings 18A, 18B can be fixed inside the rotor chamber 4. Moreover, oneor more passages 59 can be provided through or across the bearings 18A,18B so that cooling fluid can pass axially through the bearings 18A,18B. For example, as shown in FIG. 5 , the passages 59 are defined atleast in part by a cross-shaped structure of the bearings 18A, 18B, butother variations for the openings 59 may be suitable. For example, thebearings 18A, 18B can form radially-extending arms with one or more gapsdisposed between the arms. Such gaps can be enclosed peripherally by ahousing enclosing the stator assembly 2. In other embodiments, one ormore openings can be provided through the bearings 18A, 18B to definethe passages.

FIGS. 6A and 6B show one embodiment of an interface 22 between theoutput shaft 13 and the drive shaft 16. The interface 22 can comprise aconnection between a distal portion of the output shaft 13 and aproximal portion of the drive shaft 16. The distal portion of the outputshaft 13 can comprise a radially-inward taper and one or more holes 61formed through the output shaft 13. The proximal portion of the driveshaft 16 can be inserted within the lumen 55 of the output shaft 13 suchthat the lumen 55 and the inner lumen 58 of the catheter body 120A forma continuous passage. This passage can be used to advance the guidewireguide tube 20, sensors, and other instruments, or to provide fluidcommunication for cooling fluid or medications. Cooling fluid can flowproximally from the inner lumen 58 of the catheter body 120A and thefirst portion 17A of the fluid can pass outwardly about the periphery ofthe rotor 15. In some embodiments, the second portion 17B of the fluidcan pass through the lumen 55 of the output shaft 13. A sleeve 21 can bedisposed about the proximal portion of the catheter body 120A, and theseal 19 can be provided about the seal 21 to seal the distal chamber 5from the rotor chamber 4.

In the illustrated embodiments, the output shaft 13 is permanentlycoupled with, e.g., laser welded to the drive shaft 16. For example, awelding machine can access the interface 22 by way of the holes 61formed in the output shaft 13 to weld the output shaft 13 to the driveshaft 16. In other embodiments, the output shaft 13 can be secured tothe drive shaft 16 in other ways, e.g., by friction or interference fit,by adhesives, by mechanical fasteners, etc.

Although the embodiments disclosed herein have been described withreference to particular embodiments, it is to be understood that theseembodiments are merely illustrative of the principles and applicationsof the present inventions. It is therefore to be understood thatnumerous modifications can be made to the illustrative embodiments andthat other arrangements can be devised without departing from the spiritand scope of the present inventions as defined by the appended claims.Thus, it is intended that the present application cover themodifications and variations of these embodiments and their equivalents.

What is claimed is:
 1. A catheter pump system comprising: an impellerfor pumping blood; a catheter body comprising an outer lumen and aninner lumen; a drive shaft disposed inside the inner lumen and coupledwith the impeller at a distal portion of the drive shaft, the driveshaft configured such that rotation of the drive shaft causes theimpeller to rotate; a motor assembly for imparting a rotation of theimpeller through the drive shaft, the motor assembly comprising: astator carrying electrical windings; and a rotor disposed in at least aportion of the stator, the rotor mechanically coupled with a proximalportion of the drive shaft; and a cooling system for delivering coolingfluid to the pump system during operation of the pump system andreturning at least some of the delivered cooling fluid to a wastereservoir, wherein the cooling system channels cooling fluid distallythrough the outer lumen to the impeller, and wherein the cooling systemchannels cooling fluid proximally along and through a central coolingfluid channel passing through the rotor.
 2. The catheter pump system ofclaim 1, wherein a fluid flow through the outer lumen lubricates theimpeller and/or supplies fluid to a patient.
 3. The catheter pump systemof claim 1, wherein a fluid flow through the inner lumen is channeledaround the periphery of the drive shaft.
 4. The catheter pump system ofclaim 1, wherein a fluid flow through the inner lumen is channeledwithin the drive shaft.
 5. The catheter pump system of claim 1, whereinthe motor assembly includes a flow diverter, and wherein the coolingfluid is channeled from the inner lumen to a rotor chamber of the flowdiverter.
 6. The catheter pump system of claim 1, wherein the coolingsystem further channels cooling fluid proximally through a peripheralcooling fluid channel extending along an outer periphery of the rotor.7. The catheter pump system of claim 6, wherein a first portion of aproximally flowing cooling fluid is channeled through the peripheralcooling fluid channel in a gap defined between the rotor and a flowdiverter of the motor assembly, and wherein a second portion of theproximally flowing cooling fluid is channeled through the centralcooling fluid channel.
 8. The catheter pump system of claim 6, furthercomprising a flow diverter, wherein the first cooling fluid channel andthe second cooling fluid channel converge in a proximal chamber of theflow diverter.
 9. The catheter pump system of claim 6, wherein acombined flow rate of a first portion of a proximally flowing coolingfluid in the first fluid cooling channel and a second portion of theproximally flowing cooling fluid in the second fluid cooling channel iswithin a range of approximately 5.0 milliliters per hour (mL/hr) and20.0 mL/hr.
 10. The catheter pump system of claim 9, wherein thecombined flow rate of the first portion of the proximally flowingcooling fluid and the second portion of the proximally flowing coolingfluid is within a range of approximately 10.0 mL/hr and 15.0 mL/hr. 11.A catheter pump system comprising: an impeller for pumping blood; acatheter body; a drive shaft disposed inside the catheter body andcoupled with the impeller at a distal portion of the drive shaft, thedrive shaft configured such that a rotation of the drive shaft causesthe impeller to rotate; a motor assembly for imparting a rotation of theimpeller through the drive shaft, the motor assembly comprising: astator carrying electrical windings; and a rotor disposed in at least aportion of the stator, the rotor mechanically coupled with a proximalportion of the drive shaft; and a cooling system for delivering coolingfluid to the pump system during operation of the pump system andreturning at least some of the delivered cooling fluid to a wastereservoir, wherein the cooling system comprises: a first cooling fluidchannel defined about a periphery of the rotor, wherein a first portionof a proximally flowing cooling fluid is channeled through the firstcooling channel in a gap defined between the rotor and a flow diverterof the motor assembly; and a second cooling fluid channel extendingthrough the rotor, wherein a second portion of the proximally flowingcooling fluid is channeled through the second cooling fluid channeldefined by a longitudinal lumen extending through the rotor.
 12. Thecatheter pump system of claim 11, wherein a combined flow rate of thefirst portion of the proximally flowing cooling fluid and the secondportion of the proximally flowing cooling fluid is within a range ofapproximately 5.0 milliliters per hour (mL/hr) and 20.0 mL/hr.
 13. Thecatheter pump system of claim 11, wherein the combined flow rate of thefirst portion of the proximally flowing cooling fluid and the secondportion of the proximally flowing cooling fluid is within a range ofapproximately 10.0 mL/hr and 15.0 mL/hr.
 14. The catheter pump system ofclaim 11, wherein the cooling system comprises a bypass channelconfigured to channel a bypass portion of the proximally flowing coolingfluid around the motor assembly such that the bypass portion does notflow inside the motor assembly.
 15. The catheter pump system of claim14, wherein the bypass channel extends from an inner lumen of thecatheter body to one of a waste reservoir or a heat exchanger.
 16. Thecatheter pump system of claim 14, wherein a volume of the bypass portionof the proximally flowing cooling fluid in the bypass channel is lessthan a combined volume of the first portion of the proximally flowingcooling fluid and the second portion of the proximally flowing coolingfluid.
 17. The catheter pump system of claim 14, wherein the flow rateof the bypass portion is within a range of approximately 1.0 mL/hr and5.0 mL/hr.
 18. The catheter pump system of claim 14, wherein thecombined flow rate of the first portion of the proximally flowingcooling fluid and the second portion of the proximally flowing coolingfluid is within a range of approximately 5.50 mL/hr and 12.0 mL/hr. 19.The catheter pump system of claim 14, wherein the combined flow rate ofthe first portion of the proximally flowing cooling fluid and the secondportion of the proximally flowing cooling fluid is within a range ofapproximately 5.50 mL/hr and 8 mL/hr.
 20. The catheter pump system ofclaim 14, wherein the flow rate of the bypass portion is within a rangeof approximately 8.0 mL/hr and 14.0 mL/hr.
 21. The catheter pump systemof claim 14, wherein a volume of the bypass portion of the proximallyflowing cooling fluid in the bypass channel is more than a combinedvolume of the first portion of the proximally flowing cooling fluid andthe second portion of the proximally flowing cooling fluid.
 22. Thecatheter pump system of claim 14, wherein a volume of the bypass portionof the proximally flowing cooling fluid in the bypass channel is aboutequal to a combined volume of the first portion of the proximallyflowing cooling fluid and the second portion of the proximally flowingcooling fluid.